My main system with an Ipad is working fine, but when I went to connect my slave unit after several months of non use, it won't connect. I was careful to perform all updates during the time I wasn;t using the second controller, but the trouble appears to a have occured between the 3.0 an 4.0 update. I have tried connecting a usb disc to the controller with first the 3.0 update and then the 4.00 update but there has been no reaction. I did discover that in the intervening period, there was a big Android update and also I updated the DJI Go App;.  the DJI Go app seems current. Have checked cables and they are fine. Second controller has a pink light when it turns on...not sure what this means.  How do you trouble shoot this situation? How do I check the controller for the firmware that it has? Could I have fouled up something with the updates?  The controller won't work with my Ipad.

My main system with an Ipad is working fine, but when I went to connect my slave unit after several months of non use, it won't connect. I was careful to perform all updates during the time I wasn;t using the second controller, but the trouble appears to a have occured between the 3.0 an 4.0 update. I have tried connecting a usb disc to the controller with first the 3.0 update and then the 4.00 update but there has been no reaction. I did discover that in the intervening period, there was a big Android update and also I updated the DJI Go App;.  the DJI Go app seems current. Have checked cables and they are fine. Second controller has a pink light when it turns on...not sure what this means.  How do you trouble shoot this situation? How do I check the controller for the firmware that it has? Could I have fouled up something with the updates?  The controller won't work with my Ipad.